[1Ea01-05] International Online Session (hybrid oral session)

[1Ea04(2023若手女性研究者優秀賞)] Improving the efficiency of THz emissions in semiconductor and spintronic materials using surface science approaches

*Mary Clare Escaño¹ (1. Research Center for Development of Far-Infrared Region, University of Fukui)

THz radiation, which lies between the microwave and infrared region of electromagnetic spectrum, coincides with excitation of many systems making it suitable for low-energy spectroscopy. It also corresponds to the channel bandwidth of “Beyond 5G” allowing big-data transmission for large-scale automation through AI for the benefit of an old-population society. However, THz gap exists due to the lack of efficient THz emitters. Ways to improve the emission from two of our developed THz emitters are investigated using surface science approaches. We studied the low-temperature GaAs and found that the desired sub-band gap excitation originates from As-antisite defect based on theoretical/experimental STM and STS. For the second case, we studied the spintronic THz emitter made from Fe/Pt bilayer. Since, Pt is a precious metal, we use the surface-interface Rashba effect to replace Pt with a carbon layer. Results from first-principles study are compared with ARPES and spin-pumping experiment.